British Columbia Manure and Crop Nutrients A Review of Current Data and Regional Fieldwork focused on Southwest British Columbia February 26, 2015 Prepared For: British Columbia Ministry of Agriculture Contract # GSAGF2-047 1767 Angus Campbell Road Abbotsford B.C. V3G 2M3 Prepared by: Sean M. Smukler, DeLisa Lewis, Courtney Robinson and Nikki McConville Faculty of Land and Food Systems, University of British Columbia 2357 Main Mall Vancouver B.C, V6T 1Z4 With contributions from: Amy Norgaard, Nousheen Bastani, and Zineb Bazza
Transcript
British Columbia Manure and Crop
Nutrients
A Review of Current Data and Regional Fieldwork
focused on Southwest British Columbia February 26, 2015
Sean M. Smukler, DeLisa Lewis, Courtney Robinson and Nikki McConville
Faculty of Land and Food Systems,
University of British Columbia
2357 Main Mall
Vancouver B.C, V6T 1Z4
With contributions from: Amy Norgaard, Nousheen Bastani, and Zineb Bazza
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Acknowledgement This project is supported by Growing Forward 2, a federal-provincial-territorial initiative.
Disclaimer Opinions expressed in this document are those of the author and not necessarily those of Agriculture and Agri-Food Canada and the British Columbia Ministry of Agriculture. The Government of Canada, the British Columbia Ministry of Agriculture or its directors, agents, employees, or contractors will not be liable for any claims, damages, or losses of any kind whatsoever arising out of the use of, or reliance upon, this information.
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Executive Summary The overarching goal of this document is to provide updated manure and crop nutrient
information as part of a broad set of initiatives to develop nutrient management planning tools in
British Columbia (BC). A key outcome of what is reported in this document is a set of
recommended reference values for manure and crop nutrients. This information is condensed
as reference tables and can be found in complete form in appendices 1 and 2 of this report.
Manure nutrient analyses are required for calculating the agronomic balances and crop removal
balances of fields that receive manure1. In addition, crop yields and nutrient analyses of
harvestable portions of crops are required for calculating crop removal balances. This report
includes manure and crop data from a variety of sources that have been summarized and
compiled in a single dataset. The data sources included were from:
A review of literature on manure and crop types and nutrient contents from BC, other
provinces, and outside of Canada
Field data that was collected primarily in Southwest British Columbia from June 2013 to
December 2014
Unpublished BC Ministry of Agriculture manure and crop datasets
The review provides detailed summaries of the current distribution of manure and crop types in
BC, the available data on crops and manures, and an assessment of the quality of these data.
In all, we reviewed a total of 148 sources including surveys, reports, personal communications,
unpublished data, and peer reviewed publications from 1969 through 2014. The documents are
compiled in an online bibliography here (http://www.mendeley.com/groups/4193931/bc-
agricultural-nutrient-management/). We compiled data on yields, and nutrient content for 24
crops, and nutrient content of manure for 13 different manure and other soil amendment types
(e.g. compost). These data will also be made available online.
Southwest British Columbia (SWBC) was the primary focus of this review and data collection
because of its importance to agricultural production in the province. SWBC includes five
Regional Districts: Fraser Valley, Metro Vancouver, Sunshine Coast, Squamish-Lillooet, and
Powell-River Regional Districts. Decades of provincially and regionally focused research have
provided baseline nutrient data for certain manures and crops, but no comprehensive or
updated compilation of this information is currently available. These data could substantially
enhance the development of sound strategies and nutrient management tools, particularly in
SWBC, where simultaneous increases in human population, urban development, and livestock
density characterize the land base pressures.
Although the findings in this literature review and preliminary fieldwork have helped develop
summary values for manure and crop, more comprehensive fieldwork and a broader review
could help reduce the variability of these values and contribute to a more comprehensive
1 See the Nutrient Management Reference Guide for explanations of agronomic and crop removal
balances (Poon and Schmidt, 2010. Nutrient Management Reference Guide, 2nd
) for prominent forage and cereal crops grown in British
Columbia from 2005 to 2014 and the average and percent coefficient of variation (CV) for that
entire period (Statistics Canada 2014). Value are dry matter except when indicated with *. .... 23
Table 8. Forage and cereal crop yield (kg ha-1
dry weight) average, coefficient of variation
percentage (CV), minimum, maximum and number of observations in Southwest British
Columbia (SWBC) reported from field sampling (field), observations found in the literature
and British Columbia (BC) from Statistics Canada and the literature. CV is for the number of
observations except for Statistics Canada data, which is based on 10 years of reported
yields. * Provincial corn, silage was corrected for moisture content using 73% moisture from
the literature....................................................................................................................................... 23
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Table 9. Provincial average yields (kg ha-1
) for vegetables of British Columbia from 2005 to 2014
and the average and percent coefficient of variation (CV) for that entire period (Statistics
These data have been compiled in detail in a database that will be made available online and
are summarized below. This is far from a comprehensive inventory of all the data available and
is not a meta-analysis. Finally, from this review, we identify critical gaps in existing data and
provide recommendations for prioritizing data collection and analyses to enhance nutrient
management planning efforts in the future.
2. Current Understanding of Nutrient Dynamics in SWBC Southwest British Columbia (SWBC) is one of the most important agricultural regions in British
Columbia (BC) with more than 65% of BC’s total farm receipts, 87% of the poultry, and 70% of
the dairy cows in the province (BCMA 2012). This region is also one of the most intensively
managed agricultural landscapes in the country, with more livestock per unit area than any other
part of Canada (Statistics Canada 2012). Pressures to this land base are characterized by
simultaneous increases in human population, urban development, and livestock density.
Despite the overall strength of the livestock sector across Canada and in BC, beef, hog, and
dairy farm numbers in this region were down from the 2006 to 2011 agricultural census (BCMA
2012).
Animal production makes significant contributions to the economy of the region and the
province, and with its past and present viability, this agricultural sector will be at the forefront of
confronting the challenges of sustaining economic success in the face of environmental
impacts. Specific environmental impacts include air and water quality along with associated
risks to human health. More than two decades ago, researchers began tracking surplus nutrient
levels in this region from manure nitrogen (N) phosphorus (P) and potassium (K) and their
impacts on the environment (Brisbin 1995, Schreier et al. 1997, Mitchell et al. 2003, Timmenga
& Associates Inc. 2003, Chesnaux et al. 2007). Surplus nutrients unused by crops can be lost
from farm fields through a number of pathways to either water resources or the atmosphere. In
regional research documenting environmental impacts to drinking water from excess nutrients,
long-term well monitoring programs have detected groundwater NO3 concentrations in the
Abbotsford Aquifer above the Canadian Drinking Water Guideline of 10 mg NO3-N per L
(Chesnaux et al. 2007). Agricultural burning, greenhouse gas emissions, odour and manure
management are key air quality concerns linked with intensive agriculture in SWBC. The BC
Agriculture Nutrient and Air Working Group, Ministry of Environment, and Environment Canada
have contributed monitoring, assessment and best practices guides aimed to reduce negative
air quality impacts associated with agricultural operations.
Regionally specific challenges to nutrient management in SWBC linked with climate include the
limited duration (about four to six months per year) when manure can be land applied with low
or no concerns of runoff or leaching from precipitation. Active planning and adequate storage
are required for farm operations in SWBC to match manure application rates with crop demand
and to meet the challenges of avoiding losses via runoff and leaching into drinking water and
aquatic habitat resources.
While there have been numerous studies in the region that have examined various aspects of
nutrient cycling in SWBC, including aquifer NO3-N concentrations (Zebarth et al. 1998, Mitchell
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et al. 2003, Chesnaux et al. 2007), ammonia emissions (Zebarth et al. 1999), and regional
nutrient balances (Brisbin 1995, Hall and Schreier 1996, Vizcarra et al. 1997, Timmenga &
Associates Inc. 2003), there is a significant need for basic data required for many of the
calculations used for these types of analyses. Many of the previous analyses we reviewed used
the same sets of data for yield, crop nutrient content or manure nutrient content and annual
animal manure production rates.
There have been a number of studies over the last 20 years that have analyzed the nutrient
imbalance in SWBC, particularly for the Lower Fraser Valley (LFV), using a basic mass balance
approach. The majority of these studies rely on a set of data compiled through a series of
surveys that were conducted by the agricultural industry (i.e. dairy, hog, and poultry) in the early
1990s (e.g. SPFG, 1993). The first of these series of regional nutrient assessments was Brisbin
(1995). The Brisbin (1995) reports provided a detailed analysis of nutrient production, use and
fate in the LFV using a variety of sources and a mass balance nutrient model as part of an
extensive assessment of livestock manure. The data utilized in these reports were sourced from
numerous other studies conducted in the region, and the findings relied heavily on the industry
surveys. Brisbin (1995) provides nutrient contents for 18 different types of animal manures that
indicate wide ranges of values depending on the breed of animal. Hall and Schreier (1996)
provide an analysis of the impacts of urbanization and agricultural intensification on water
quality in the region. Their analysis (1996) provides typical application rates of manure (205 kg
N ha-1 yr-1, 153 kg P205 ha-1 yr-1, 158 kg K2O ha-1 yr-1), and fertilizer (68 kg N ha-1 yr-1, 38 kg P205
ha-1 yr-1, 41 kg K2O ha-1 yr-1) that indicates substantial reliance on manures for fertilization. They
also reported typical uptakes for corn and grass in this study that are far lower than typical
manure and fertilizer applications rates.
Subsequently Vizcarra (1997) completed a similar analysis, but with the specific objectives of
determining the distribution of leachable nitrogen and of estimating the nitrogen concentration in
groundwater recharges. Their study utilized a water and nitrogen mass balance in five-year
intervals between 1971 and 1991 and relied on a variety of data sources for application rates
and concentrations (Agriculture Canada 1979; Kowalenko, 1987; Schepers & Mosier, 1991). A
couple years later, Zebarth et al. (1999b) conducted an extensive analysis of the environmental
outcomes of nutrient surpluses in the LFV and compared several different potential
management scenarios for the region. To develop the reference scenario, Zebarth et al. (1999b)
utilized 1991 Census of Agriculture data and “typical 1991” animal-and crop-production
practices. Rates for animal excretion in the Zebarth et al. (1999b) study were compiled from a
wide range of literature (Yeck et al.,1975; Brumm et al.,1978; Bulley & Holbek, 1982; Overcash
et al., 1983; Hahn & Rosentreter, 1989). Zebarth et al. (1999) compiled estimates for inorganic
fertilizer, manure and crop removal rate for N for 20 geographical districts in the LFV.
In a more recent study, Timmenga & Associates Inc. (2003) again provided a detailed
assessment of manure and nutrient surpluses in the LFV based on the data produced from the
industry surveys carried out in the 1990s. Their study calculated the requirement for NPK based
on the crop needs as recommended in BC Ministry of Agriculture Forestry and Foods
(BCMAFF) publications, used the 2001 Census of Agriculture for total animal numbers, included
North Carolina production coefficients for livestock housing and production systems to estimate
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manure nutrient tonnage, and finally, depended on data for manure based on nutrient analysis
provided by Government of British Columbia Resource Management Branch.
Other studies have provided more specific analysis of either manure or crops, but our review
indicates the literature does not provide a comprehensive understanding for the broad diversity
of crops grown and livestock raised in SWBC. In her Master’s Thesis, Weinberg (1987) provided
nutrient content and yields for silage corn, sweet corn, potatoes, alfalfa and wheat. Others have
since provided data on yields and nutrient content for sweet corn (Krzic et al. 2001), forage
(Bittman et al. 2000) corn, broccoli (Bowen et al. 1999), and raspberries (Dean et al. 2000). The
Soil Management Handbook for the LFV (Bertrand et al, 1991) provides NPK values for six
different manure types, and the handbook for soil management in the Okanagan and
Similkameen Valleys (Gough et al. 1994) provides data for five different livestock and poultry
manures and from different types of storage. Despite the breadth of this previous nutrient
management research, the question remains: Is the data that has been produced over the last
40 years of manure and crop research suitable for effectively managing SWBC’s current
diversity and intensity of crop and livestock production? A key purpose of this nutrient
management focused literature review is therefore to compile updated information on regionally
tested nutrient data with the overall intent to provide a solid foundation for nutrient management
planning tools for the diverse types of agricultural operations that characterize particularly
SWBC and the province as a whole.
3. Data and Gaps in Current Knowledge Base To assess the current need for nutrient content and yield data we compiled available Statistics
Canada (2012) agricultural survey data for crop area and animals in production in 2011 that was
reported for the SWBC and BC. We have organized this data in two main sections, Manure and
Crops, which are then assessed by manure or crop types in separate subsections. In the
Manure section, we calculate manure production for the region using the number of animals for
the reported in the Statistics Canada (2012) survey for 2011 and annual animal manure
production coefficients (Hofmann & Beaulieu, 2006). We then provide information about the
nutrient contents of the major manure types that are land-applied. For the Crops section, we
review the historic yields that are compiled by Statistics Canada (2015) at the provincial scale
for forage and cereal crops, fruits and vegetables, and compare these to yields compiled from
analysis of production specifically in SWBC. We then summarize the nutrient content and
uptake by particular crops within each subsection.
3.1 Manure
In this section, we reviewed the data found for manure nutrient content by animal type (beef and
dairy, poultry, swine and other types of animals). In our review, we identified 63 studies that
provided data on manure in SWBC, 15 of which provided adequate data. Most of the data
compiled was for manure N content, followed by P and then K.
In 2011 SWBC manure production was primarily from dairy and poultry sectors (Figure 1). While
SWBC accounted for only 31% of the total estimated manure production for the province, 70%
of the dairy cow manure and 80% of the poultry manure was produced in the region. Other
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types of animals raised in the region included: horses and ponies, goats, mink, lambs, ewes,
and rams which accounted for 21% of the manure production for these animal types. Beef
cattle, most of which are found outside of SWBC, produced the 34% of the calculated manure of
the province. We estimate almost all of the beef cow manure (97%) is produced outside of
SWBC.
Figure 1. The distribution of total animal manures produced in Southwest British Columbia (SWBC) and British Columbia (BC) on the day of the 2011 census. Calculated using the number of animals reported (Statistics Canada 2012) and annual animal manure production coefficients (Hofmann & Beaulieu 2006). *Other cattle see figure 2 for details. †Other see figure 5 for details.
3.1.1 Dairy and Beef Cattle
The vast majority of cattle manure produced in SWBC was from dairy production and heifers, 1
year and over while the majority of cattle manure for the province was from beef cows (Figure
2). The literature had a number of studies that included dairy manure nutrient contents and
almost none that had reported values for beef manure. Of the 137 field samples of cattle
manure we recorded, <20% were from beef. Statistics Canada (2012) also reports the numbers
of calves under a year old, and heifers, steers and bulls over a year old, but none of the
literature we identified separated nutrient values for these animal types specifically nor did we
differentiate field sampling by these animal types.
Figure 2. The distribution of total cattle manure produced in Southwest British Columbia (SWBC) and British Columbia (BC) on the day of the 2011 census. Calculated using the number of animals reported (Statistics Canada 2012) and annual animal manure production coefficients (Hofmann & Beaulieu 2006)
We recorded 223 observations for dairy manure including 120 field samples. Concentrations of
nutrients in dairy manure varied significantly (p<0.001) with the level of moisture, and are
reported here by moisture content classes (Table 1). Manure with moisture content between 82-
100% could be a slurry of water and manure that has separated out from the solids. Dairy
manure with ≤82% moisture would be a thick slurry or solid. For all nutrients except NH4-N
values increased as moisture content decreased. Nutrient values for NH4-N were smallest at
the lowest and highest moisture contents and largest for manure with moisture ranging from 94-
96%. Within each of the moisture groups, the range of values varied greatly by nutrient. Field
sampling for dairy manure was consistent for the majority of samples with values found in the
literature and the combined average did not differ substantially from that of the field data with
the exception of N and NH4-N values for manure <72%. In some cases the manure studies we
reviewed agitated the manure before sampling but our field samples here were taken at distinct
layers of the liquid or settled solid material, which may explain some of these differences.
Variability for solid dairy manures was particularly high with CVs for nutrients on average >66%.
Given the extent of field sampling compared to results from the literature, only the field values
reported here are recommended for “book values” (Appendix 1. 1).
Table 1. Dairy manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by manure moisture ranges.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Solid
<72%
Field 0.76 43 0.03 133 317 133 0.20 26 0.43 87 9 High
Literature 0.13 39 0.06 41 633 41 18 Low
72-82%
Field 0.39 58 0.08 95 797 95 0.10 77 0.30 68 27 High
Literature 0.04 400 0.39 2
Liquid
82-90%
Field 0.36 71 0.12 47 1202 47 0.10 88 0.27 35 19 Medium
Literature 0.21 123 0.01 132 0.17 133 0.64 9 Medium
Field 0.09 58 0.05 46 497 46 0.02 59 0.12 26 15 Medium
In total we have recorded 22 field samples of feedlot beef manure, all but two from outside of
SWBC. The data therefore are not distinguished by region (Table 2). The beef cattle manure
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results were significantly different (p<0.05) by moisture class but were all highly variable,
particularly for NH4-N. Nutrient contents were highest for manures in the 72-82% moisture range
with the exception of K, which was highest for ≤72%. These data are recommended for “book
values” but additional sampling would likely improve the confidence (Appendix 1. 2)
Table 2. Feedlot beef cattle manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by manure moisture ranges.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
All 0.47 93 0.02 159 164 159 0.12 108 0.36 81 22 High
3.1.2 Poultry
SWBC accounts for the majority (88%) of poultry manure production BC (Figure 3). We
estimate the majority of poultry manure production in SWBC is from broilers, followed by turkeys
and laying hens over 19 weeks old. In our review we found a variety of categories for recording
poultry manure nutrient contents. In most cases, the studies we reviewed used only basic
classes such as poultry, or chicken and turkey, though in some studies the type of use was
identified: breeder, broiler, or layer. In a one study poultry was differentiated by commercial egg,
or hatching egg.
Figure 3. The distribution of total poultry manure produced in Southwest British Columbia (SWBC) and British Columbia (BC) on the day of the 2011 census. Calculated using the number of animals reported (Statistics Canada 2012) and annual animal manure production coefficients (Hofmann & Beaulieu 2006)
We recorded a total of 149 observations of poultry manure nutrient content 126 of which were
from field data. The only variable that significantly differentiated poultry manures was the
storage type for broilers (Table 3). Broiler manure that was sampled from Indoor sites would
likely have been directly from the barn and is assumed to be fresher than sampled from Outdoor
storage. Indoor manure was on average 56% higher in N (p<0.001) and 31% higher in P
(p=0.056) but was not statistically different for NH4-N or K. Poultry manure nutrient contents
were in general fairly variable with Outdoor broiler having “high” variability. Our field data and
the literature matched well except for layers and Hatching Egg which was not sampled. The
Layer manure average NH4-N was 70% higher from the data collected from the literature than
our field data and was also much less variable. Future sampling should focus on providing
better resolution for these two classes and for now only field data are recommended for “book
values” (Appendix 1. 3).
Table 3. Chicken manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of all four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by breed and storage type. Indoor storage indicating manure is coming from poultry barns and may be fresh whereas outdoor storage is likely to be aged.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Literature 2.50 40 0.45 40 4490 40 0.97 43 1.06 31 17 Medium
Broiler breeder
Field 1.07 56 0.29 75 2858 75 0.72 77 0.80 49 4 Medium
Hatching egg
Literature 1.96 0.41 4050 1.31 1.0 1
Layer
Field 2.26 40 0.39 99 3889 99 1.13 69 1.51 49 17 Medium
Literature 2.31 72 0.66 56 6616 56 1.00 33 1.08 1 16 Medium
We recorded a total of 30 observations for turkey manure, 16 of which were field data. Turkey
manure nutrient contents were significantly different depending on the age of the manure when
it was sampled (Table 4). N content was 100% higher (p<0.01) in fresh (≤7 weeks old) than in
aged manure (>7 weeks old). This was also true of NH4-N, which was 96% higher (p<0.001), P
was 82% higher (p<0.001) and K 120% higher (p<0.001). For aged manure the CV ranged
from 31 to 65% and for fresh from 19 to 67%. Although there were only four values found in the
literature, they were substantially higher in value for all nutrients particularly N and NH4-N. The
differences and the relative amount of turkey manure warrant additional data collection with
better resolution on the age, storage and bedding and only the aged and fresh classes are
recommended as “book values” (Appendix 1. 4).
Table 4. Turkey manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by the age of the manure when sampled.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Literature 4.20 23 0.99 44 9938 44 1.24 1.20 4 Medium
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3.1.3 Swine
Swine in SWBC is classified into five groups which represent 65% of the swine manure
production in BC. Weaner and nursing pigs are primarily found outside of SWBC (Figure 4).
Roughly half of the boar manure produced in the province is in SWBC. Most of the data we
found in our review was classified as generally swine or hog, representing operations that may
have included multiple swine groups or stages of production. A few studies defined the manures
by farrow to finish, farrow to weaner, or grower/finisher. We did not find any studies that
included specifically boar manure.
Figure 4. The distribution of total swine manure produced in Southwest British Columbia (SWBC) and British Columbia (BC) on the day of the 2011 census. Calculated using the number of animals reported (Statistics Canada 2012) and annual animal manure production coefficients (Hofmann & Beaulieu 2006)
Overall, we recorded 29 observations for swine manure, 21 of which were from field data. We
found extreme differences between the nutrient concentrations of solid and liquid swine manure
in the field data. N, P and K content were 2.6 (p<0.01), 3.7 (p<0.05) and 3.5 (p<0.001) times
higher in solid manure than liquid while NH4-N was 4.2 (p<0.05) times lower (Table 5). Other
researchers have also differentiated swine manure by whether it was stored in a covered or
uncovered pit (Gough et al. 1994) but we found no significant differences based on our data.
Both the liquid and solid swine manure had high variability in nutrient values, P was by far the
most variable followed by NH4-N, K and finally N. The 8 values reported in the literature were all
for liquid swine manure for different types of swine manure, farrow to finish, farrow to weaner,
and grower/finisher. Field data did not differentiate by these categories and although some of
the values are different we do not know the variability of the data for the literature nor the
sample size. All but two observations (one from field and one from literature data) were from
SWBC so there is likely no representation of the sizable weaner or nursing pig manure that is
produced in the province. Future sampling of swine could help differentiate manure nutrient
contents by manure storage, the age/size class of the animal and the location and for now only
field data is recommended as “book values” based on solid or liquid status (Appendix 1.5).
Table 5. Hog manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by moisture content (≤82% moisture = solid, >82% moisture = liquid).
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Farrow to Finish (Liquid)
Literature 0.30 0.14 0.22 1
Farrow to Weaner (Liquid)
Literature 0.36 0.10 0.15 1
Grower/Finisher (Liquid)
Literature 0.57 0.17 0.25 1
Hog (Liquid)
Field 0.33 37 0.22 58 2211 58 0.10 118 0.15 61 13 High
Literature 0.36 15 0.30 29 2980 29 0.12 29 0.28 75 5 Medium
Hog (Solid)
Field 0.86 54 0.05 98 525 98 0.42 102 0.50 74 8 High
3.1.4 Other Animals and Compost
There are a number of other animals being raised in SWBC, but combined likely account for
only ~5% of the total manure produced at the time of the 2011 census (Figure 5). This number
is likely slightly larger as some of the animals raised in SWBC and elsewhere in the province do
not have manure coefficients. Animals in this category that did have coefficients include horses
and ponies, mink, goat, lambs, and ewes, in order of manure production. For these animals
SWBC produces 21% of the total manure in the province as most of the animals of these type
are raised outside of SWBC with the exception of mink, which is entirely found in the region.
The “other” animals that did not have manure coefficients were small in population (<10,000
head) deer, rams, llamas and alpacas, rabbits and bison (buffalo). Also included in this section
are other transformed fates of animal manures including compost and anaerobic digester
products.
Figure 5. The distribution of total ‘other’ animal manure produced in Southwest British Columbia (SWBC) and British Columbia (BC) on the day of the 2011 census. Calculated using the number of animals reported (Statistics Canada 2012) and annual animal manure production coefficients (Hofmann & Beaulieu 2006)
-
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
Horsesandponies Lambs Ewes Goats Mink
Man
ureProduced(Mgyear
-1)
SWBC
BC
20
Sample sizes for field data of the “other” category were small and limited the possibility of
further differentiating the materials reported in this section and our literature review did not
target these types (Table 6). Some of these materials sampled had very high nutrient contents,
particularly duck and mink. The one digester sample showed high NH4-N and very low N, P,
and K suggesting the material could be an important resource for providing available nitrogen.
Variability for all of these classes was high and in the case of the digester and mink, unknown,
given we only had one sample of each. As composting and the use of digesters are increasing
in the province getting better data for these will be important. Although the nutrient content of
duck and mink manure is high, and could be a valuable manure amendment, the numbers of
animals in the SWBC and the province remain relatively low. Given the limited number of
samples only horse manure nutrient contents at this time can be recommended as “book
values” (Appendix 1.5).
Table 6. The nutrient content of six types of manures or other soil amendments (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High).
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
According to Statistics Canada survey data 67% of the 60,111 hectares in crop production
(forage and cereal crops, vegetables, and fruit) in SWBC in 2011 was used to grow forage and
cereal crops, 21% was used for fruit production, and 12% for vegetables (Figure 6). While
SWBC represents only 10% of the total cropping area in BC, vegetable production in the region
in 2011 accounted 74% of the vegetable production area in the province and more than 54% of
the fruit production area. Although forage and cereal crops are a sizeable amount of the
cropland in SWBC, this was only 7% of the total production in BC in 2011. This provincial crop
distribution reflects the relatively mild maritime climate and fertile valley bottom soils found in
SWBC.
In our review we found a wide range of literature on crop yield and nutrient contents, and
although our search was not exhaustive there were noticeable gaps in data. Overall in our
review, yield data was far more accessible than crop nutrient content. From the 27 studies that
include yield data for SWBC we complied 358 observations for crop yield (most of which were
for forage and cereal crops). The relative number of observations we compiled did not entirely
reflect the current cropping distribution, 85% of our observations were for forage and cereal
crops, 12% for vegetables and only 1% for fruit despite its land area and economic importance.
Figure 6. Distribution of crop production in the Southwest British Columbia (SWBC) by area (left) and percent of BC crop grown in SWBC (right) in 2011 by area (Statistics Canada 2012)
3.2.1 Crop Area and Yields
Two major challenges for nutrient management are targeting a feasible yield goal for a given
growing season and from there, determining expected nutrient removal from the soil in the
harvested biomass. Historically, the federal government has collected information on crop yields
that have been reported by farmers randomly selected across the province (Statistics Canada,
2012). The yield information is then averaged for a given time period and made publically
accessible. While the data collected on reported yields for the province provides a useful
temporal trend, spatial variability is not accounted for, and the efficacy of disaggregating the
data by region by crop type is unclear. Disaggregation of the yield data for those crops grown in
different regions of the province with wide variations in soil and climate conditions, would
provide a step towards nutrient management planning with feasible yield goals for those crops.
Forageandcereals67%
Fruit21%
Vegetables12%
CropDistribu oninSWBC
0
10
20
30
40
50
60
70
80
Forageandcereals Fruit Vegetables
Percent
PercentofBCCropsGrowninSWBC
22
For example, potatoes and forage crops are grown in the Fraser Valley as well as in the
Thompson-Nicola regional districts, yet are likely to have distinct yield averages given the
differences in soil and climates between the regions. For crops with strong regional production
limitations such as cranberries grown in SWBC, the provincial yield data collection and
averages likely provides adequate planning information. In their study of BC crop yields,
Morrison et al. (2011) uses the regional dominance of certain types of crop production to
disaggregate provincial yields with varying degrees of efficacy. Here we use a similar approach
to assess the validity of applying provincial yield averages specifically for SWBC and compare
these data to those from found in the literature and field sampling.
In addition to compiling published and unpublished crop data we sampled select crops and feed
mainly from SWBC. Crops were harvested from farmer’s fields who were willing to participate in
the survey. As close to harvest as possible transects were established across fields and 3-6
plots were harvested and weighed in the field. Sub-samples were taken for moisture and
nutrient content analysis. Sampling of blueberry fruit was done for two cultivars (Duke and
Reka) at two locations repeatedly throughout the season as close to the producers harvest as
possible (5-6 times).
3.2.2 Forage and Cereal crops
The dominant forage and cereal crops farmed in the SWBC in terms of land use area are fodder
crops for livestock. Field area devoted to tame hay and fodder crops represent 59% of the
SWBC growing region but only 14% of the tame hay and fodder production area in the province
(Figure 7). Silage corn in 2011 was 23% of the forage and cereal crop area in SWBC and 66%
of the total production area of silage corn in the province. Alfalfa was 12% of the forage and
cereal crop production area in SWBC in 2011 but this represents only 2% of the alfalfa
production area of the province. The other forage and cereal crops grown in the region comprise
in total only 6% of the forage and cereal crops in the area.
Figure 7. The area of the top 10 most prominently produced forage and cereals in British Columbia (BC) and Southwest British Columbia (SWBC) in 2011 (Statistics Canada 2012).
-
50,000
100,000
150,000
200,000
250,000
Alfalfaandalfalfa
mixtures
Allothertamehayandfoddercrops
Canola(rapeseed)
Oats Totalwheat Barley Forageseedforseed
Cornforsilage
Dryfieldpeas
Hectares SWBC
BC
23
In terms of overall productivity, silage corn has the highest average yield (49,160 kg ha-1) of all
forage and cereal crops grown in the SWBC within the last 10 years (Table 7). Two crops with
the highest yield variability from year-to-year were mixed grains and peas but the number of
years these harvests reported were limited.
Table 7. Provincial average yields (kg ha-1
) for prominent forage and cereal crops grown in British Columbia from 2005 to 2014 and the average and percent coefficient of variation (CV) for that entire period (Statistics Canada 2014). Value are dry matter except when indicated with *.
For forage and cereal crops, the number of studies and available data for SWBC were fairly
reflective of the dominance and importance of hay and fodder crops in the region. We recorded
more than 250 observations for corn and grass forage. Data from field sampling, Statistics
Canada and the literature were closely aligned with the exception of wheat, which was 3.5 times
higher in studies reported from SWBC (Table 8). Given the massive area planted in forage and
cereal crops outside of SWBC that likely contributes disproportionately to provincial yields,
further spatial disaggregation for regional yields across the province would likely provide more
effective nutrient management planning.
Table 8. Forage and cereal crop yield (kg ha-1
dry weight) average, coefficient of variation percentage (CV), minimum, maximum and number of observations in Southwest British Columbia (SWBC) reported from field sampling (field), observations found in the literature and British Columbia (BC) from Statistics Canada and the literature. CV is for the number of observations except for Statistics Canada data, which is based on 10 years of reported yields. * Provincial corn, silage was corrected for moisture content using 73% moisture from the literature.
Field crops Location Average CV (%) Min. Max. Count Source
Corn, silage SWBC 12,010 54 6,288 18,976 3 Field Data
Corn, silage SWBC 15,068 20 8,600 20,000 40 Literature
Corn, silage* BC 13,473 15 10,913 18,068 10 Statistics Canada
Forage grass/legume SWBC 3,811 47 1,590 6,030 14 Literature
Orchardgrass BC 13,856 20 10,525 17,357 16 Literature
Orchardgrass SWBC 14,183 6 12,911 15,332 16 Literature
Tame hay BC 4,086 15 3,360 5,440 10 Statistics Canada
Wheat BC 5,238 37 2,900 8,100 8 Literature
Wheat BC 2,810 29 1,800 4,000 10 Statistics Canada
Wheat SWBC 9,838 61 4,200 21,300 13 Literature
24
3.2.3 Vegetable Crops
The most predominant vegetable crop grown in the SWBC is potato. The number of hectares
planted to potatoes, while only 5% of the vegetable crop area in SWBC in 2011 was 66% of the
potato production area of the province. Potato planting area is followed by sweet corn, which
comprises 13% of the total land under vegetable crop production but accounted for 73% of the
sweet corn planted across the province in 2011. Green and wax beans are the third largest
vegetable crop in SWBC, with 10% of the vegetable production area and 94% of the area
planted provincially. Most of the remaining vegetable crop area (44%) is comprised of a
relatively equal distribution of Other (i.e. unspecified) vegetables, broccoli, Brussels sprouts,
squash and zucchini, green peas, pumpkins, cabbage and carrots. Most of provincial area
planted to these vegetables was concentrated in SWBC in 2011. For example 96% of the
Brussels sprouts, 96% of Chinese cabbage, and 91% of the broccoli planted in BC was in
SWBC.
Figure 8. Area of the top 10 most prominently produced vegetables in British Columbia (BC) and Southwest British Columbia (SWBC) in 2011 (Statistics Canada 2012).
Statistics Canada data (2014) indicates fairly stable yields for most vegetable crops over a ten
year period (Table 9) with the exception of Brussels sprouts and carrots. Potatoes had the most
consistent yield with a CV of only 5%. Yield variability for parsnips and celery were substantially
higher than other vegetables, with CVs of 64% and 53% respectively. For both of these crops as
well as a number of other vegetables, yields records were not available for the entirety of the
most recent 10-year period. In some cases this absence in the records was due to unreliable
yields data (i.e. carrots 2009 and 2014).
In our review of yields for SWBC general, we found there was relatively little data available for
vegetables. Of the studies we reviewed, the majority of the data was for sweet corn (15
observations) and broccoli (2 observations). For all other vegetables crops in SWBC, we were
able to compile only one to two yield observations if any (Table 10).
-
500
1,000
1,500
2,000
2,500
3,000
3,500
Potatoes Sweetcorn Greenandwaxbeans
Othervegetables
Squashandzucchini
Pumpkins Broccoli Greenpeas Brusselssprouts
Carrots
Hectares SWBC
BC
25
Table 9. Provincial average yields (kg ha-1
) for vegetables of British Columbia from 2005 to 2014 and the average and percent coefficient of variation (CV) for that entire period (Statistics Canada 2012).
Dry onions 41,600 x 33,100 23,000 F x 33,000 35,000 F F 33,140 20 Other melons (cantaloupes, winter melons, etcetera) 14,300 20,200 20,500 22,400 F F 24,900 F 33,000 F 22,550 28
Rhubarb 17,700 14,200 15,600 13,900 F F 16,300 11,900 x x 14,933 14 Rutabagas and turnips 23,900 20,400 15,600 22,800 F 19,900 20,600 13,800 25,800 29,900 21,411 23
Watermelon 14,800 16,800 15,200 9,600 15,400 F 26,800 18,900 22,000 F 17,438 30
Cabbage, Chinese (bok-choy, napa, etcetera) .. .. 10,700 10,700
Cabbage, regular .. .. 28,900 28,900
x - Suppressed to meet the confidentiality requirements of the Statistics Act
F - Too unreliable to be published
1. Includes Chinese cabbage and regular cabbage.
2. Includes baby carrots and regular carrots.
3. Includes leaf lettuce and head lettuce.
To convert to pounds per acre divide multiply by 0.892
Source: Statistics Canada. Table 001-0013 - Area, production and farm gate value of vegetables, annual (accessed: January 30, 2015)
26
The yield averages for SWBC that we did compile were in some cases far higher than the 10-
year averages reported by Statistics Canada across the province. The research design and
intent that formed the majority of available regional yield averages in our literature review are
likely sources of these differences. Much of yield data we reviewed was from experimental
studies based in this region that aimed to determine optimal crop variety, management, and/or
fertilization regimes. Despite these differences, we compiled a sizable number of observations
for two crops that might warrant accurate comparisons. SWBC broccoli yields were more than
1.5 times higher than provincial 10-year average while sweet corn was 41% higher than 10-year
average, close to the maximum recorded during that period. Potato yields averaged from field
data collected in 2013-14 for SWBC were 19% higher than the 10-year provincial average and
as high as 42% greater for late season cultivars. From the data we compiled it is unclear
whether provincial yields for vegetables effectively represent those for SWBC, but given the
likely dominance of SWBC vegetables in the random selection of producers across the
province, 10-year yield averages are probably representative for most crops with the exception
of sweet corn and broccoli. Given the area of potatoes planted outside SWBC analysis of other
regions and cultivars are likely to enhance nutrient management planning in other regions.
Table 10. Vegetable crop yield (kg ha-1
) compared for various data sources for Southwest British Columbia (SWBC), British Columbia (BC) and Washington State (WA). Yield averages, coefficient of variation percentage (CV), minimum, maximum and number of observations (No.) are illustrated. CV is calculated for the number of observations except for Statistics Canada data, which is based on 10 years of reported yields.
Vegetable Crop Location Average CV Min. Max. No. Source
Beans SWBC 10,213 21 8,243 12,465 3 Field
Beans BC 7,150 18 5,500 9,200 10 Statistics Canada
Broccoli SWBC 10,000 28 8,000 12,000 2 Literature
Broccoli BC 5,888 18 4,500 7,900 8 Statistics Canada
Cabbage SWBC 47,500 37 35,000 60,000 2 Literature
Cabbage BC 28,900 0 28,900 28,900 1 Statistics Canada
Carrots SWBC 21,509 30 16,031 28,621 3 Field
Carrots SWBC 35,000 20 30,000 40,000 2 Literature
Carrots BC 33,350 30 26,900 53,200 6 Statistics Canada
Cauliflower SWBC 12,500 40 9,000 16,000 2 Literature
Cauliflower BC 9,238 15 7,500 11,400 8 Statistics Canada
Corn, sweet SWBC 10,864 72 0 22,700 15 Literature
Corn, sweet BC 7,690 18 5,600 10,500 10 Statistics Canada
Lettuce SWBC 50,000 28 40,000 60,000 2 Literature
Lettuce BC 26,390 13 21,300 32,100 10 Statistics Canada
Onion SWBC 50,000 14 45,000 55,000 2 Literature
Onions BC 33,140 20 23,000 41,600 5 Statistics Canada
Potato BC 31,995 5 30,207 34,746 10 Statistics Canada
Potatoes SWBC 38,092 38 18,186 90,026 28 Field
Potatoes SWBC 45,500 30 30,000 56,500 3 Literature
Potatoes Early SWBC 24,737 32 18,186 33,413 3 Field
Potatoes Late SWBC 45,603 46 26,400 90,026 9 Field
Potatoes Mid SWBC 36,235 23 24,773 47,333 12 Field
3.2.4 Fruits, Berries and Nuts
Blueberries were by far the dominant fruit crop produced in SWBC in 2011. 65% of the total
hectares in SWBC under fruit production was in blueberries (Figure 9). Cranberries and
raspberries are the next most prominent crops, consisting of 19% and 13% respectively of
SWBC. Provincial production of these three fruit crops is almost entirely located in SWBC. The
planted area in SWBC in 2011 of blueberries represent 97%, cranberries 91%, and raspberries
27
92% of provincial production area. The remaining fruit types account for only 4% of the total
land area in fruit production.
Figure 9. The area of prominently produced fruits in British Columbia (BC) and Southwest British Columbia (SWBC) in 2011 (Statistics Canada 2012).
Provincial fruit yields were determined from Statistics Canada (2014) data by dividing marketed
production by total cultivated area. The calculated yield ranges from year to year were fairly
stable for most fruit (Table 11). Watermelon, apricots and sweet cherries have the highest
variances in their yields with CVs of 30%, 29% and 27% respectively. In contrast, raspberries
and nectarines have had a fairly consistent yield between 2005 and 2014 (11% CV). There were
a number of fruit crop studies reviewed for the SWBC (12), but only a few observations from the
review were clearly scalable to a reliable per hectare yield and data from neighbouring
Washington State (WA) have also been included for comparison (USDA 2014).
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Blueberries
Apples
Grapes
Cranberries
Raspberries
Cherries(sweet)
Peaches
Strawberries
Pears
Plums&prunes
Hectares SWBC
BC
28
Table 11. Provincial average yields (Mg ha-1
) for fruit crops grown in British Columbia from 2005 to 2014 and the average and percent coefficient of variation (CV) for that entire period. Values determined from total yields divided by total production area (Statistics Canada 2012).
Watermelon 14.8 16.8 15.2 9.6 15.4 F 26.8 18.9 22 F 17.4 30
F Too unreliable to be published
E Use with caution
x Suppressed to meet the confidentiality requirements of the Statistics Act
.. Not available
1
Conversion factors used for 1 bushel of apples from 1926 to 1964 equals 45.0 pounds, 1965 equals 44.5 pounds, 1966 equals 44.0 pounds, 1967 equals 43.5 pounds, 1968 equals 43.0 pounds, 1969 equals 42.5 pounds, from 1970 on equals 42.0 pounds.
2 The value of the crop from 1984 onward is not comparable to previous years because of a change in reporting techniques for New Brunswick only.
3 Prior to 1987, total production includes figures from on-farm land and unmanaged Crown land. As of 1987, only on-farm production and value are available. Unmanaged Crown land is excluded beginning in 1987.
4 As of April 27, 1983, revisions back to 1926 in British Columbia were carried out to reflect that 1 quart equals 1.25 pounds.
5 Cultivated area includes bearing and non-bearing area.
6 Includes low bush blueberries and high bush blueberries.
7 Includes table grapes and wine grapes.
Overall calculated provincial yields were lower than those reported in the literature, from USDA
or field data (Table 12). The one exception was provincial cranberries yields, which were 67%
larger than WA. In some cases the yield differences were small, peach yields for example were
only 18% higher in WA and raspberries 19%. However, raspberry average yield found in the
literature for SWBC was more than twice that of the ten-year averages reported for the province.
Apple yields were more than 1.5 times higher and pears more than 2 times higher in WA. Field
data for blueberries were also 2 times higher than provincial yields indicating either regional
and/or cultivar variability. It may be that WA is much more productive than BC for fruit
production but given the large discrepancy between other data sources, the lack of data
compiled in this review, and the relative economic importance of fruit and berries, further review
and additional study is recommended.
29
Table 12. Fruits yield (Mg ha-1
) compared for various data sources for Southwest British Columbia (SWBC), British Columbia (BC) and Washington State (WA). Yield averages, coefficient of variation percentage (CV), minimum, maximum and number of observations (No.) are illustrated. CV is calculated for the number of observations except for Statistics Canada data, which is based on 10 years of reported yields.
Fruit Location Average CV Min. Max. Count Source
Apple BC 25.39 14 16.57 29.85 10 Statistics Canada
Apple Washington State 42.7 USDA
Blueberry BC 5.53 18 4.23 7.75 10 Statistics Canada
Blueberry Washington State 8.8 12.8 6.3 10.2 10 USDA
Blueberry SWBC 13.51 30 8.78 18.27 12 Field
Blueberry, Duke SWBC 9.71 6 8.78 10.59 6 Field
Blueberry, Reka SWBC 17.31 4 16.34 18.27 6 Field
Cherries, sour BC 4.39 15 3.93 4.86 2 Statistics Canada
Cherries, sour Washington State 9.5 USDA
Cherries, sweet BC 7.87 27 4.57 10.48 8 Statistics Canada
Cherries, sweet Washington State 10.8 USDA
Cranberry BC 13.96 16 10.40 16.38 8 Statistics Canada
Cranberry US 8.4 10.1 7.2 9.6 10 USDA
Grapes BC 5.42 12 4.46 6.38 10 Statistics Canada
Grapes, wine Washington State 10.5 USDA
Peach BC 10.46 13 8.52 12.33 10 Statistics Canada
Peach Washington State 12.32 USDA
Pear BC 20.49 13 17.41 24.16 10 Statistics Canada
Pear Washington State 46.6 USDA
Raspberry BC 6.16 11 5.34 7.14 10 Statistics Canada
Raspberry SWBC 13.93 46 8.00 20.80 3 Literature
Raspberry Washington State 7.3 9.1 6.4 8.3 10 USDA
Strawberry BC 4.8 15.5 3.9 6.0 10 Statistics Canada
Strawberry Washington State 8.9 USDA
3.3 Crop Nutrient Content
Similar to our findings of inconsistent availability of yield data in the literature across crop types,
we found a sizeable amount of nutrient content data for some crops types, while for others we
found little to nothing available. The vast majority of nutrient content data was for forage and
cereal crops, particularly forage grass sourced from unpublished Ministry of Agriculture datasets
collected over 8 years (1992-2000) from the Cariboo regional district. Far fewer nutrient content
values were found for vegetables and fruits.
The nutrient content data for some forage and cereal crops was fairly consistent, while for
others, there was large variability in the data (Table 13). The highest N content was found in
alfalfa forage (hay and silage) and the lowest corn silage. Overall the variability for N contents
were low with an average CV for all crops of 31%. Forage grass was the exception with a high
range of values and a CV of 98%. High P content was found in haylage but also in alfalfa
forages while freshly harvested grass had the highest K values. The variability of P and K was
lower the N with an average CV of 24 and 26% respectively. The number of field samples
relative to those from other datasets was small and only in a few cases (e.g. hay, alfalfa)
provides additional data or increases the resolution of existing data substantially. We therefore
30
compress the field and literature data into a single data point where there is overlap to provide a
summary table (Appendix 2.1).
Table 13. Average moisture and nutrient content (% by dry weight) of forages and cereals, percent coefficient of variation (CV), and number of observations in British Columbia. Samples were taken either from the field at harvest or from storage. Values were determined from either field data (field) or from literature or unpublished datasets (literature).
Moisture N (%) P (%) K (%)
Crop Average CV No. Average CV No. Average CV No. Average CV No.
In total we have compiled 50 observations for vegetable nutrient content, primarily from field
samples for only 7 of the 25 vegetable crops reported grown in SWBC (Table 14). Although the
sample size was small, the variability was for all vegetable crops medium to low, with an
average CV for N of 48%, P 28% and K 25%. Sample sizes for sweet corn and green peas
were too small to be reliable (n=1) and although carrots, beans and squash had small sample
sizes CVs were for all nutrients was <35%. In 2014 three types of varieties were sampled for
potatoes, early, mid and late season to assess differences in crop removal. While there was
some variability in the nutrient content between these varieties only mid season potatoes were
significantly lower in P (p<0.001). Although there were no significant differences in yields or
moisture there were significant differences in nutrient removals. P removal from the harvest of
late season potatoes was 60% higher (p<0.05) than mid and 100% higher than early season
varieties (Figure 10). K removal for late season potato varieties was only higher than early
season (p<0.05).
Table 14. Average moisture and nutrient content (% dry weight) of vegetables, percent coefficient of variation (CV), and number of observations in Southwest British Columbia.
Moisture N (%) P (%) K (%)
Crop Average CV No. Average CV No. Average CV No. Average CV No.
) for three groups of varieties, early, mid and late season. Letters indicate significant differences (p<0.05).
0.00
50.00
100.00
150.00
200.00
250.00
300.00
N P K
CropRemovalkgha-
1
Early
Mid
Late
a
b b
y
xy
x
32
There was little fruit nutrient content information available in the literature for the region. Some
studies provided information on fruit nutrients but only a few studies provided appropriate data
(Dean et al. 2000). Nutrient contents for fruit were determined by field sampling of blueberries,
and blueberry leaves were sampled for additional information (Table 15).
Whereas the nutrient concentrations in the harvested fruit represent crop nutrient removals, leaf
tissue content is used to guide fertilizer applications (Strik 2013) and samples ranged from 1.3
to 2.0% N but on average were below the recommended sufficiency level between of 1.76-2.0%
(Strik 2013). Average values for P were however in the range of sufficiency (0.11-.4%) as was K
(0.41-0.7%) (Strik 2013). Four different varieties of blueberry fruit were sampled with small
variation between nutrient contents between varieties. For varieties with multiple samples (Duke
and Reka) we found low variation within the samples with CVs for nutrient contents all nutrient
contents <15%.
Table 15. Average moisture and nutrient content (%) of small fruit, percent coefficient of variation (CV), and number of observations in Southwest British Columbia.
Moisture N (%) P (%) K (%)
Crop Average CV No. Average CV No. Average CV No. Average CV No.
When converting these nutrient contents to nutrients removed per harvested fruit (kg fruit Mg-1
wet fruit) our results fell within the range reported by Strik (2013) for N and K for both Reka and
Duke varieties but were six to nine times greater for P (Table 16). There were significant
differences between nutrient removed in the harvest between varieties. The estimated amount
of N removed was 43% higher (p<0.001) in Duke than Reka, and 10% higher for K (p<0.05).
Table 16. Nitrogen (N), phosphorus (P) and potassium (K) content per Mg of harvested fruit (wet weight) for two blueberry varieties in Southwest British Columbia compared to data from Oregon. Letters indicate significant differences between varieties (p<0.05)
Fruit by Source Nutrients kg Mg-1 wet fruit
Strik 2013 N P K
Blueberry (low) 0.65 0.10 0.70
Blueberry (high) 1.35 0.15 1.10
Field Data 2014
Reka 0.94b 0.85 0.86b
Duke 1.34a 0.85 0.94a
33
Nutrient content can vary enormously throughout the growing season depending on the crop.
Many of the observations made here did not include the timing of the nutrient content analysis,
thus limiting the utility of the data. Further analysis of the data compiled should attempt to
categorize the timing of nutrient analysis and management (e.g. fertilizer application rates) if
possible.
4. Conclusion and Recommendations The data that we have compiled here is highly variable for some manure and crop types both in
terms of the coverage of the data and the results. The literature in general is dominated by data
for forage and cereal crops, and fruit and vegetable data is not as readily available. We have
used broad categorizations of both manure and crop data to provide averages and the
associated variability. There are certainly gaps in what we have compiled (e.g. limited fruit and
vegetable data) and it is likely that additional data on both manure and crops does exist.
Manure data compiled here was highly variable and in some cases too limited to provide
conclusive estimates for particular animals or finer categories (e.g. by moisture contents).
Manure nutrient contents vary greatly as there are a large number of factors that impact
nutrients in the final product. These factors include the animal breed, feed quality and type,
methods to collect and store the manure, climate, the duration of storage, and the mechanisms
and timing for applying the manure (Chastain et al. 2003). To further complicate predicting
manure nutrient content, sample values can vary substantially by the sampling and laboratory
methods. In a statewide survey of manure in Colorado, Davis et al. (2002) estimated based on
the variability in the data they collected, that 25 sub-samples would be required to assess
manure nutrients with a 10% margin of error. Based on this analysis, Davis et al. (2002) argued
for building a database of manure nutrient content for the state. The data compiled here clearly
support such an effort.
From the data from the literature we compiled, it is unclear whether provincial yields for
vegetables effectively represent those for SWBC. This review suggests, however, that 10-year
yield averages are probably representative for most vegetable crops with the potential exception
of sweet corn and broccoli. Given the limited yield data compiled for this review and the relative
economic importance of fruit and berries, further review and additional field studies are
recommended, with the caveat that, given the dominance of SWBC production of blueberries
and cranberries, documented provincial yields may also be representative of those of the
region.
What is noticeably missing from forage and cereal crop data was information on alfalfa
production, which represents 12% of the forage and cereal crop production area in SWBC. The
few yield reports we found indicated that yields local to SWBC could be much higher than the
averages for reported at the provincial scale. While several nutrient management studies in
SWBC have included the cooperation of area potato growers, returning crop yield data for those
nutrient management focused projects was not a priority of the initiatives (e.g. Temple, Lewis &
Bomke, 2010; Kowalenko et al., 2007). Filling in and updating this yield information for SWBC
34
growers was a targeted component of this study and results suggest there are substantial
differences between regional and provincial yields.
Crop nutrient content information compiled in this review are limited and variable. Plant nutrient
uptake can vary substantially depending on the genetics of the variety, climate, soils and
management, all of which interact to impact plant nutrition and ultimately crop yields and
nutrient removal (Jones 2009). Assessing plant nutrients can be challenging as the content
changes throughout the growing season. The small number of samples limited our ability to
further categorize the crop types by any of the factors (e.g. fertilizer application rates) that may
characterize content and crop removal. Our field data, which targeted potatoes in SWBC did
show significant differences in crop nutrient removal for different varieties, specifically for P and
K. Our analysis of blueberry nutrient contents also show that there are significant differences in
varieties in terms of the nutrients removed in the harvested fruit. While the utility of nutrient
removal information for fruit crops may be limited for field and farm level management these
numbers would enhance regional nutrient analysis. There remains a clear gap in nutrient
content and removal data for fruit crops, particularly blueberries and cranberries that will likely
require future field sampling.
Numerous institutions have long recognized the limitations of “book values” for fertility
management, and the consensus recommendation is that site-specific analysis of soil, manure
and crop is best for developing management plans (Davis et al. 2002, Chastain et al. 2003).
Developing collective datasets at a regional scale can help in the effort to optimize crop
production for multiple outcomes, including income, ease of operation and environmental
sustainability. There are a number of examples where institutions have developed online
databases to enhance this process. For example the Crop Composition Database v4.2
developed by the International Life Sciences Institute provides a global database of the
nutritional composition for various crops, primarily to aid in health planning, but could be a
model for livestock nutrition. The Manitoba Agriculture, Food and Rural Development
(MAFRD) designed the Manure Application Rate Calculator (MARC) 2008 software to help with
manure management for Manitoba. These platforms serve as examples of various approaches
that could be used to enhance farmer’s nutrient management planning but a provincially specific
software would need to be designed to address the crop mix and associated nutrient demands
of BC. Such software would enable users to develop multiple plans for multiple operations by
accessing an extensive database of nutrient analyses.
Ensuring a planning tool will enhance farmer’s efficiency is critical to maximize adoption and
utility for farm operations. It is clear that dairy farmers in BC are actively analyzing their feed
(personal communication, 2013) to optimize production. It is unclear however, how much and of
what quality, sampling is being done on manures before application. Developing a system that
provides farmers with enhanced planning capabilities that simultaneously generates data that
can be analyzed with enough spatial and temporal resolution, could effectively increase the BC
Ministry of Agriculture’s capacity to provide accurate planning information. The data compiled in
this review can serve as a starting point for developing a comprehensive nutrient database.
There are certainly other historical datasets that may be added, and what has been collected
35
could be further reviewed for key information, e.g. manure handling and storage and greater
resolution for manure and crop values. Specifically, our recommendations are:
Targeted data collection should continue for manure and crop types that were not
represented or represented in low numbers.
A framework should be developed to continue to build this nutrient database with the
goal to create a provincially comprehensive dataset. This province-wide dataset would
record basic metadata of crops and manure and include specific information on the crop
variety, soil type and manure storage used, bedding, feed and age.
Additional review and quality control of unpublished crop yield information should
continue in an effort to provide more accurate reference values for crop removal
balances.
As the database grows, future analysis should focus on additional categorizations of manure
and crops that are focused on reduced variability in reference values. A more robust dataset on
manure categories will also enable the analysis of spatial and temporal trends. An important
next step may be to assess the sensitivity of management options at the field, farm or regional
scale to determine to variations in “book values” to determine the importance of future sampling
efforts.
36
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Bittman, S., Kowalenko, G. and Hunt, D. 2000. Phosphorus Deficiency in Seedling Corn - Crop
Rotation Considerations. Better Crops 84:3.
Bowen, P. A., B. J. Zebarth, and P. M. A. Toivonen. 1999. Dynamics of nitrogen and dry-matter
partitioning and accumulation in broccoli ( Brassica oleracea var . italica ) in relation to
extractable soil inorganic nitrogen. Canadian Journal of Plant Science 79:277–286.
Brisbin, P. E. 1995. Agricultural Nutrient Management in the Lower Fraser Valley: Management
of Agricultural Wastes (Report 4).
Chastain, J. P., J. J. Camberato, J. E. Albrecht, and J. Adams. 2003. Swine Manure Production
and Nutrient Content. Pages 1–18 CAMM Poultry.
Chesnaux, R., D. M. Allen, and G. Graham. 2007. Assessment of the impact of nutrient
management practices on nitrate contamination in the Abbotsford-Sumas aquifer.
Environmental science & technology 41:7229–34.
Conyers, M. K., M. J. Bell, N. S. Wilhelm, R. Bell, R. M. Norton, and C. Walker. 2013. Making
Better Fertiliser Decisions for Cropping Systems in Australia (BFDC): knowledge gaps
and lessons learnt. Crop and Pasture Science 64:539.
Davis, J., K. Iversen, and M. Vigil. 2002. Nutrient variability in manures: Implications for
sampling and regional database creation. Journal of Soil and Water 57:473–478.
Dean, D. M., B. J. Zebarth, C. G. Kowalenko, J. W. Paul, and K. Chipperfield. 2000a. Poultry
manure effects on soil nitrogen processes and nitrogen accumulation in red raspberry.
Canadian Journal of Plant Science 80:849–860.
Gough, N. A., G. A. Hughes-Games, and D. C. Nikkel. 1994. Soil Management Handbook For
The Okanagan And Similkameen Valleys.
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Krzic, M., M. Fortin, and A. A. Bomke. 2001. Sweet Corn Tillage-Planting Systems in a Humid
Maritime Climate of British Columbia. Journal of Sustainable Agriculture 19:25–39.
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Strik, B. C. 2013. Nutrient Management of Raspberries & Blueberries - A Summary. Pages 1–6.
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British Columbia. Environmental management 21:269–82.
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Zebarth, B.J., B. Hii, H. Liebscher, K. Chipperfield, J.W. Paul, G. Grove, S.Y. Szeto, and K.
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38
Appendix 1: Manure Nutrient Values Appendix 1. 1.Dairy manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by manure moisture ranges.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Appendix 1. 2. Feedlot beef cattle manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by manure moisture ranges.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
All 0.47 93 0.02 159 164 159 0.12 108 0.36 81 22 High
Appendix 1. 3. Chicken manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of all four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by breed and storage type. Indoor storage indicating manure is coming from poultry barns and may be fresh whereas outdoor storage is likely to be aged.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Appendix 1. 4. Turkey manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by the age of the manure when sampled.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV
Aged (≤7 weeks old 0.87 41 0.13 65 1281 65 0.44 31 0.59 64 9 Medium
Fresh (>7 weeks old 1.79 42 0.25 67 2518 67 0.79 29 1.31 19 7 Medium
Appendix 1. 5. Hog and horse manure nutrient content (as is basis) showing the average and percent coefficient of variation (CV) for total nitrogen (N), ammonium (NH4-N), phosphorus (P), potassium (K), the number of samples taken (No.) and an assessment of variability of the data based on the average CV of the four nutrients (<33% = Low, 34-66% = Medium, >67% High). Data is categorized by moisture content.
Class
N (%) NH4-N (%) NH4-N (ppm) P (%) K (%)
No. Variability Average CV Average CV Average CV Average CV Average CV Hog Liquid (> 82%
Bertrand et al. 1991 Soil management handbook for the Lower Fraser Valley 6 6 6
Bhandral et al. 2008 Emissions of nitrous oxide after application of dairy slurry on bare soil and perennial grass in a maritime climate
Bittman and Kowalenko 1999
Surface-Banded and Broadcast Dairy Manure Effects on Tall Fescue Yield and Nitrogen Uptake 18 18
Bittman et al. 2006 Starter Phosphorous and Broadcast Nutrients on Corn with Contrasting Colonization by Mycorrhizae 3 3 3
Bittman et al. 2007 Agronomic effects of multi-year surface-banding of dairy slurry on grass 2 1
Bittman et al. 2012 Precision Placement of Separated Dairy Sludge Improves Early Phosphorus Nutrition and Growth in Corn (Zea mays L.) 3 3 3
Bomke and Lowe 1991 Trace Element Uptake by Two British Columbia Forages as affected by Poultry Manure Application
Dean et al. 2000 Poultry Manure Effects on Soil Nitrogen Processes and Nitrogen Accumulation in Red Raspberry 3 3
Gough et al. 1994 Soil Management Handbook for the Okanagan and Similkameen Valleys 7 7
Khan 1986 Effects of Rates and Methods of Swine Slurry Application on Crop N Uptake and N Distribution in the Soil 3 3 3
Lau et al. 2008
Development of ammonia emission factors for the land application of poultry manure in the Lower Fraser Valley of British Columbia 3 3
Nolan 2002 Poultry Manure and Composted Yard Trimmings for Organic Vegetable Production in Delta, B.C. 1 1
Smukler et al. 2015 BC Nutrient Database Field Data 170 170 176 176 Sustainable Poultry Farming Group 2004 Sustainable Poultry Farming Group Fact Sheet 4 4 4 4 Timmenga and Associates Inc. 2003
Evaluation of Options for Fraser Valley Poultry Manure Utilization 2 2 2
Zebarth et al. 1996
Influence of the Time and Rate of Liquid-Manure Application on Yield and Nitrogen Utilisation of Silage Corn in South Coastal British Columbia
Total 380 314 368 352
42
Appendix 2: Crop Nutrient Values
Appendix 2. 1. Average moisture and nutrient content (% by dry weight) of forages and cereals, percent coefficient of variation (CV), and number of observations in British Columbia. Samples were taken either from the field at harvest or from storage.
Moisture N (%) P (%) K (%)
Crop Average CV No. Average CV No. Average CV No. Average CV No.
Appendix 2. 2. Average moisture and nutrient content (% dry weight) of vegetables, percent coefficient of variation (CV), and number of observations in Southwest British Columbia.
Moisture N (%) P (%) K (%)
Crop Average CV No. Average CV No. Average CV No. Average CV No.
Appendix 2. 3. Bibliography of crop yield and nutrient content indicating sources of information
Author Date Title
Yield N content
P content
K content
BCMOA 2003 Overview of Vegetable Production in BC 1 0 0 0
BCMOA unpublished Feed analysis data 0 1 1 1
Bhandral et al. 2008 Emissions of nitrous oxide after application of dairy slurry on bare soil and perennial grass in a maritime climate
1 1 0 0
Bittaman and Kowalenko 2000 Within-Season Grass Herbage Crude-Protein- and Nitrate-N Concentrations as Affected by Rates and Seasonal Distribution of Fertiliser Nitrogen in a High Yearly Rainfall Climate
0 1 0 0
Bittman 2012 Reduced Tillage in the Fraser Valley 1 0 0 0
Bittman and Kowalenko 1998 Whole-season Grass Response to and Recovery of Nitrogen Applied at Various Rates and Distributions in a High Rainfall Environment
1 1 0 0
Bittman and Kowalenko 1999 Within-season Grass Herbage Crude-Protein and Nitrate-N Concentrations as Affected by Rates and Seasonal Distribution of Fertilizer Nitrogen in a High Yearly Rainfall Climate
0 1 0 0
Bittman et al. 1999 Advanced Forage Management - A production guide for coastal British Columbia and the Pacific Northwest
1 0 0 0
Bittman et al. 1999 Surface-Banded and Broadcast Dairy Manure Effects on Tall Fescue Yield and Nitrogen Uptake
1 0 0 0
Bittman et al. 2000 Phosphorous Deficiency in Seedling Corn - Crop Rotation Considerations
1 0 1 0
Bittman et al. 2000 Phosphorus Deficiency in Seedling Corn: Crop Rotation Considerations
1 0 0 0
Bittman et al. 2004 Season of Year Effect on Response of Orchgardgrass to N fertilizer in a Maritime Climate
1 1 0 0
Bittman et al. 2005 Cheam-VR Orchardgrass 1 0 0 0
Bittman et al. 2006 Chilliwack-VR Orchardgrass 1 0 0 0
Bittman et al. 2006 Haida-VR Orchardgrass 1 0 0 0
Bittman et al. 2006 Starter Phosphorous and Broadcast Nutrients on Corn with Contrasting Colonization by Mycorrhizae
1 0 1 0
Bittman et al. 2007 Agronomic effects of multi-year surface-banding of dairy slurry on grass
1 0 0 0
Bittman et al. 2012 Precision Placement of Separated Dairy Sludge Improves Early Phosphorus Nutrition and Growth in Corn (Zea mays L.)
1 0 1 0
Bomke and Bertrand 1983 Response of an Orchard Grass-Perennial Ryegrass Sward to Rate and Method of Urea and Ammonium Nitrate Application
1 0 0 0
Bomke and Lowe 1991 Trace Element Uptake by Two British Columbia Forages as affected by Poultry Manure Application
1 0 0 0
Bomke and Temple 1994 Winter Wheat Growth and Nitrogen Demand in South Coastal BC
1 0 0 0
Bowen et al. 1998 Dynamics of nitrogen and dry-matter partitioning and accumulation in broccoli (Brassica oleracea var. italica) in relation to extractable soil inorganic nitrogen
1 1 0 0
Dean et al. 2000 Poultry Manure Effects on Soil Nitrogen Processes and Nitrogen Accumulation in Red Raspberry
1 1 0 0
Dyck et al. 2004 Agronomic Performance of Hard Red Spring Wheat Isolines Sensitive and Insensitive to Photoperiod
1 0 0 0
Fairey 1982 Influence of Population-Density and Hybrid Maturity on Productivity and Quality of Forage Maize
1 1 0 0
Fairey 1985 Productivity and Quality of Perennial and Hybrid Ryegrass, Orchardgrass, and Reed Canarygrass Grown in the Lower Mainland of British Columbia
1 0 0 0
Fairey 1985 Productivity, Quality and Persistence of Perennial Ryegrass as Influenced by Cutting/Fertility Management and Ploidy
1 1 0 0
Fisher et al. 1993 A comparison of tall fescue and orchardgrass silages for lactating cows
0 0 1 1
44
Author Date Title
Yield N content
P content
K content
Gaye and Maurer 1991 Modified Transplant Production Techniques to Increase Yield and Improve Earliness of Brussels-Sprouts
1 0 0 0
Grant et al. 2012 Crop yield and nitrogen concentration with controlled release urea and split applications of nitrogen as compared to non-coated urea applied seeding
1 1 0 0
Guthrie and Bomke 1980 Nitrification Inhibition by N-Serve and ATC in Soils of Varying Texture
1 1 0 0
Khan 1986 Effects of Rates and Methods of Swine Slurry Application on Crop N Uptake and N Distribution in the Soil
1 0 0 0
Kowalenko 2000 Nitrogen pools and processes in agricultural systems of Coastal British Columbia — A review of published research
1 0 0 0
Krzic and Bomke 1996 Zero Till Seeding of Corn into Winter Cover Crops in the Western Fraser Valley
1 1 0 0
Krzic et al. 2001 Sweet Corn Tillage-Planting Systems in a Humid Maritime Climate of British Columbia
1 0 0 0
Kuchta 1999 The effect of nitrogen, water and alley management strategies on nitrate and water loss from the root zone in perennial raspberry
1 0 0 0
Ma et al. 2004 Corn Growth and Development (Chapter 7: Advanced Silage Corn Management)
1 0 0 0
Maynard and Bomke 1980 The Response of a Grass-Legume Sward to Poultry Manure
0 1 0 1
Neilsen et al. 2009 Organic fruit production in British Columbia 1 0 0 0
Nolan 2002 Poultry Manure and Composted Yard Trimmings for Organic Vegetable Production in Delta, B.C.
0 1 0 0
Ritchie Smith Feeds, Inc. 2013 Forage Analysis - Ritchie Smith Feeds, Inc 0 0 1 1
Ritchie Smith Feeds, Inc. 2014 Forage Analysis - Ritchie Smith Feeds, Inc 0 0 1 1
Schmidt 2008 Assessment of nutrient management Benefical Management Practices (BMPS) for poultry manure on high fertility fields in the Fraser Valley
1 0 0 0
Smukler et al. 2015 BC Nutrient Database Field Data 1 1 1 1
Thompson 2013 Yield and Nutritive Value of Irrigated Tall Fescue Compared with Orchardgrass: in Monocultures or Mixed with Alfalfa
1 0 0 0
Tucker et al. 2012 Effects of Livestock Grazing on Forage Production, Forage Quality and Soils Properties at Six Sites in the Southern Interior
1 0 0 0
van Dalfsen and Gaye 1999 Yield from Hand and Mechanical Harvesting of Highbush Blueberries in British Columbia
1 0 0 0
Weinberg 1987 Improving nitrogen fertilizer recommendations for arable crops in the Lower Faser Valley
1 1 0 0
Wilkeem et al. 1993 An overview of the forage resource and beef production on Crown land in British Columbia
1 0 0 0
Zebarth et al. 1995 Influence of Nitrogen Fertilisation on Broccoli yield, Nitrogen Accumulation and Apparent Fertiliser-Nitrogen Recovery
1 0 0 0
Zebarth et al. 1996 Influence of the Time and Rate of Liquid-Manure Application on Yield and Nitrogen Utilisation of Silage Corn in South Coastal British Columbia
1 0 0 0
Zebarth et al. 2001 Fertilizer nitrogen recommendations for silage corn in high-fertility environment based on pre-sidedress soil nitrate test
